Fluid pressure clutch



July 18', 1944. w. P. scHMl'rTER 2,354,174

FLUID PRESSURE CLUTCH Filed sept. 15. 1941 FIGJ.

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t BY

ATTORNEY.

Patented July 18, 1944 FLUID PRESSURE CLUTCH walter P. schmltter, wauwatosa, wis., assigner to The Falk Corporation, Milwaukee, Wis., a corporation of Wisconsin Application September 15, 1941, Serial No. 410,883

3 Claims.

This invention relates to fluid pressure` clutches of the type ,involving'a fluid pressure container expandable to provide a releasable driving connection between the driving and driven clutch elements.

One object of the present invention is to provide a centrifugally controlled fluid pressure clutch of the type mentioned.

Another object is to provide, in a fluid pressure clutch of the type mentioned, a device responsive to the speed of the driving element for controlling the clutch. With such anarrangement the driver may start free from load resistance and thereafter automatically assume the load upon attaining a predetermined speed.

Another object is to provide a iluid pressure clutch under the control of a centrifugally controlled valve.

Other more specific objects and advantages l will appear from4 the following description of an illustrative embodiment of the present invention.

In the accompanying drawing: Figure l is a sectional view of a fluid pressure clutch embodying the present invention.

Fig. 2 is a sectional view of thecontrol valve shown in Fig. 1, illustrating the on position thereof.

The clutch selected for illustration comprises an inner element I6 in the form of a drum attached to a flanged collar II keyed or otherwise 'fixed to a driven shaft I2; and an outer element I3 in the form of a drum disposed concentrically of and surrounding the inner drum I0 and'attached to a disk I4 keyed'or otherwise xed to a drive shaft I5.

A flexible fluid pressure container I6, preferably attached to one of the drums and expandable into gripping, engagement with the other drum, provides a releasable driving-connection therebetween. In this instance the fluid pressure container I6 comprises a hollow annular gland of rubber, preferably internally reinforced by embedded cords or fabric as in ordinary pneumatic tire construction, vulcanized or otherwise surface bonded to and within the outer drum I3 and expandable into frictional gripping engagement with the inner drum IIJ upon admission of fluid pressure thereto. The gland I6 is preferably provided on its inner'face with appropriate friction material I'I attached thereto.

vThe admission and exhaust of fluid, preferably air` to and from the gland I6 is through an appropriable tube I8 which in this instance extends through the Wall of thedrum into and through municates through appropriate piping I9 with an axial duct or channel 20 in the outer. end of a rod- 2I which is fixed to and extends radially from the drive shaft I5. A second axial duct or channel 22 in the lower end of the rod 2I communicates at all times with an appropriate iluid pressure source through a non-rotating pipe 23, a swivel joint 24- of a well known type, andappropriate ducts 25 inthedrive shaft I5. The pipe 23 is shown loosely extending axially through the driven shaft I2.

An appropriate valve, of which the rod 2I constitutes a part, controls the application and discharge of fluid pressure to and from the gland I6. The valve shown comprises a sleeve 26 fitted to slide axially along the radial rod 2| and having an internal annular channel 21 extending lengthwise thereof. Packing rings 28 pressed against the ends of the channel 21 by an interposed coil spring 29 seal the joints between the ends of the sleeve 26 and the rod 2I. A spring 30 acting against the upper or outer end of the sleeve 2B urges the same downwardly or inwardly vagainst a stop collar 3I fixed to the rod, but the sleeve is centrifugally urged outwardly against the pressure of the spring 29 during rotation of the drive shaft I5.

In all positions of the sleeve 26 along the rod 2|,the channel 21 communicates with the uid pressure duct 22 through radial ports or channels 32 disposed at the upper end of the duct. 'I'he upper duct 2li communicates with similar ports 33, so positioned as to be uncovered by the sleeve 26 when the latter is in its inner position against the collar 3 I. The ports or channels 33 thus function as exhaust ports through which the fluid pressure in the gland I6 is released when the sleeve 26 is in the inner position just described. However, as the sleeve 26 moves uoutwardly under the centrifugal forces resulting from rotation of the drive shaft I5, the channel 26 is ultimately brought into communication with the ports 33, 'as indicated in'Fig. 2.A Fluid pressure is then transmitted through the ports 33, duct 29, piping I9,

and tube I8 into the gland I6 to expand the latter and thereby close the clutch. This of course occurs when the drive shaft I5 has attained a certain speed predetermined by theweight of the sleeve 26 and the degree of compression in the spring 30.

It will thus be noted that the clutch is normally open when the drive shaft I5 is at rest, since the the outergwall of the gland. The tube I8 com- 55 sleeve 26 is then normally retracted and gland I6 is open to the atmosphere through the ports 33 and therefore retracted .from the drum l0.

Therefore, at the time of starting, the drive shaft |5-is disconnected from the driven shaft I2 and free from the resistance offered by the torque load on the latter. As the drive shaft I5 comes up to speed, however, the valve sleeve 26 functions automatically to eil'ect communication between the ports I3 and the channel 21 and thereby eiect transmission of fluid pressure to the gland IB to expand the latter and thereby close the clutch.

Various changes may be made in the embodiment of the invention hereinabove specifically described Without departing from or sacrificing the advantages of the invention as deilned in the appended claims.

I claim:

1. A clutch comprising a pair of driving and driven clutch members, fluid pressure means expandable to effect a driving relation between said members and contractable to break said relation, and means including a valve having an integral part centrifugally urged away from the axis of rotation of said members for controlling said iluid pressure means. l

2. A clutch comprising a pair oi' driving and driven rotary clutch members. fluid pressure means operable to close and open said clutch, and means including a. valve having channelled members relatively movable to control said nuid pressure means, one of said channelled members being movable toward and from the axis o! rotation of WALTER P. SCHMITTER. 

